Question: In 28 years, Luis will be 5 times as old as he is right now. How old is he right now?
Explanation: We can use the given information to write down an equation about Luis's age. Let Luis's age be $l$ In 28 years, he will be $l + 28$ years old. At that time, he will also be $5 l$ years old. Writing this information as an equation, we get: $l + 28 = 5 l$ Solving for $l$ , we get: $4 l = 28$ $l = 7$.